1. Field of the Invention
This invention relates to a process for the manufacture of phenol-isobutyraldehyde condensation products. More specifically, this invention relates to such a process wherein problems presented by odor are eliminated or substantially reduced.
2. Prior Art
Condensation products of phenols and isobutyraldehyde are well known in the prior art. They are generally prepared by condensation of isobutyraldehyde with the phenol in the presence of acid catalysts, subsequent neutralization of the resultant products and removal of the resulting reaction water by distillation. Such process is described in German Published Applications Nos. 2,805,763 and 2,805,684.
A drawback of the above described manufacturing methods is the formation of by-products which are produced in quantities of up to 2 percent. These include, for instance, 2,2-dimethylcoumaran which result in considerable odor problems in many technical applications, for instance, in the printing ink industry.
Accordingly, it is a purpose of the instant invention to provide a process for the manufacture of phenol-isobutyraldehyde condensation products wherein odor problems are eliminated or substantially reduced.